The present invention relates to a process of liquefaction of coal in a chemical manner without employing high temperature and high pressure.
For liquefying coal, there have been known processes, wherein coal is decomposed under high temperature and high pressure. However, in these processes, very large amount of energy is required to obtain liquefied product useful as a resource of energy and is therefore unprofitable. Moreover, it is impossible to carry out the liquefaction of coal in large scale by these processes.
Therefore, the object of the present invention is to propose a novel process for liquefying coal, which does not show such defects.
The inventor has found, that coal can be liquefied at an yield of up to about 80% of its original weight, by a procedure, wherein coal crushed into granular form is soaked in aqueous solution of sodium hydroxide so as to penetrate the solution into the coal body and is subsequently pulverized on a pulverizer, after it is taken out and dried, to a particle size smaller than 100-mesh, and then, the so obtained coal powder is mixed with an aqueous solution containing sodium hydroxide and organic carboxylic acid by agitating the mixture and the mixture is subsequently held still for a sufficient time until the coal becomes ominous of liquefaction, and finally, the mixture is heated at a temperature from 90.degree. to 150.degree. C. with further addition of water.